This section provides background information related to the present disclosure which is not necessarily prior art.
A blower assembly has been provided for a heating, ventilation, and air conditioning (HVAC) unit for a vehicle or any industrial applications. One of the conventional blower assemblies may include a centrifugal fan and a scroll casing. The centrifugal fan may define an air inlet at a center thereof for receipt of airflow. The centrifugal fan may define a plurality of air outlets about an outer periphery thereof. A plurality of blades may be provided at the air outlets in order to direct airflow exiting the air outlets. The centrifugal fan may rotate about an axis at an axial center of the air inlet.
The scroll casing may include a side scroll casing, generally extending around a portion of the centrifugal fan from a scroll starting position to a scroll ending position. An air outlet of the blower assembly may extend from the scroll ending position to an outlet aperture at which airflow exits the blower assembly. The air outlet may define the outlet aperture. As airflow may pass through such blower assembly, various noises may occur such as an air-rush noise. The air-rush noise may be dominated by a high frequency broad-band noise in the frequency range of about 1500 Hertz to about 6000 Hertz. Major source may be the turbulence induced noise and location of this noise may be in the air outlet of the blower assembly.